We became aware of an issue where recent snapd doesn’t function very well if used in the old-named ubuntu-core snap instead of the new-named core snap. We need to address this before the release of 2.25 and 2.26.

This seems to be caused by hard-coding core as the name of the snap we look at looking for snap-confine and other execute-from-core assets.

There are a few obvious places where this is a factor (re-exec checks, usage of snap-confine, detection of the apparmor profile) but there may be others. We should spend the better part of tomorrow focusing on this issue.

The issue is simple, we started hard-coding the-name-of-the-snap-shipping-snapd as core. In the past we preferred core but also had a fallback to ubuntu-core. We no longer have that. The when it broke part is less clear but I plan to find out (tomorrow)

The problem is that ubuntu-core is very much a second class citizen by now.

We only need a somewhat recent version so that we have a snapd in ubuntu-core that will auto-transition the existing ubuntu-core to the proper core snap. However to do this we don’t actually need to release ubuntu-core regularly (and keep all the compatibility baggage in snapd). The population of ubuntu-core users is very small and you only get it by default if you start with ubuntu 16.04.1 (snapd 2.0.10) which is obsolete by now and probably has more problems).